In 1943 some IS 1 tanks were rearmed with a new 122 mm gun and was in action was in February 1944. The turrest had been sligthly redesigned (flatterned). After tests of several vehicles, it was decided at the end of 1944 to improve the armour which later led to the IS-3. The IS-2 has been compared unfavourably to both the Tiger and Königstiger in armor and firepower, though it should be kept in mind that the IS-2 was in the same weight-class as the German Panther. In the spring of 1944 the modified version IS-2m appeared with a new, simpler and better angled bow casting. A total of 3.483 of IS-1/2 were manufactured.